Impinging jets are used extensively in various applications such as heating, cooling, or drying of paper, pulp, printers ink, food, tissue, textiles, chemicals, film, and in the cooling of electronic equipment, turbine, and combustor components. The attraction of these jet systems lies in their ability to control local transport rates by varying various parameters such as the jet diameter, jet-to-impingement surface spacing, and jet-to-jet spacing in addition to the flow rate and temperature. Systems that incorporate impinging jets generally consist of in-line, orifice or slot jets. A reservoir upstream of the nozzle provides the necessary flow pressure, and the flow exits the nozzle and impinges directly on an impingement surface.
However, these slot jets do not permit a means to control the force exerted on the impingement surface. For example, a standard air jet apparatus that transfers air directly perpendicular to the impingement surface such as wet paper web in a paper-drying application may exert too much force on the paper, resulting in breakage. These slot jets also do not provide uniform local heat transfer to the impingement surface, resulting in uneven drying patterns.